I had a damaged disk that's encrypted with CoreStorage / FileVault. DiskWarrior was unable to operate on it while encrypted, obviously (“This is an offline, unavailable Core Storage disk.”); but the
diskutil corestorage unlockVolume [UUID] operation both unlocks and mounts the volume.
With a damaged disk like this, I'd really like to avoid mounting the filesystem before working on it — I'd just like to unlock it so I can proceed with recovery tools.
Is there any way to enter the disk's password without causing it to subsequently be mounted by OS X?